含峭壁V形峡谷对地震SH波散射的解析解  

An analytical solution to the scattering of plane SH waves by a V-shaped canyon with cliffs

作　　者：张宁[1,2] 潘家琐 代登辉 高玉峰[1,2] ZHANG Ning;PAN JiaSuo;DAI DengHui;GAO YuFeng(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学土木与交通学院,南京210098

出　　处：《地球物理学报》2021年第3期896-906,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金面上项目(52078184);国家自然科学基金重点项目(41630638)资助.

摘　　要：地表地形常引起地震动的局部放大,这是由于地震波传播至局部地形时产生了散射现象.本文利用波函数展开方法和区域匹配技术,提出了含峭壁V形峡谷对平面SH波散射问题的解析解,并进行了退化验证.通过频域内的参数分析,揭示了峭壁深度、入射波频率和角度等因素对峡谷场地地面运动的影响规律,发现上部峭壁会增强峡谷对地震动的地形放大效应.研究结果不仅为数值方法提供了验证基准,还可为含峭壁峡谷周边建筑物的抗震设计提供顺河向地震动输入.Local amplification of ground motions often occurs due to the scattering of seismic waves when propagating around surface topography.This paper,using the method of wave function expansion and the technique of region matching,proposes an analytical solution to the scattering of plane SH waves by a V-shaped canyon with cliffs and validates it by the degradation.Based on a parametric analysis in the frequency domain,the effects of cliff depth,incident wave frequency and angle on the ground motion of the canyon site are revealed.It is found that the upper cliff can enhances the amplification effect of the canyon on ground motions.The research results provide not only a reference for numerical methods,but also an earthquake input in the upstream-downstream direction for the seismic design of buildings around canyons with cliffs.

关 键 词：地形效应 平面SH波 散射 波函数展开 解析解 

分 类 号：P315[天文地球—地震学]